Modern lifestyle, excessive chemicalization of agricultural products, excessive processing and refining of food, cause a decrease in daily intake of magnesium, cation with an extremely important role in prevention and treatment of many diseases. As a result, there arises the need for extra magnesium intake in the form of dietary supplements. In this study were evaluated the physical and chemical stability of magnesium-containing tablets, depending on the active compound and the excipients used. Magnesium tablets in the form of orotate, lactate, citrate, oxide and hydroxide were taken into study and physical and chemical stability were observed over the validity period, at 6 and at 12 months after expiry date. There were no changes in physical and chemical stability during the validity period of the studied tablets. At 6 months after the expiry date, were observed variations in chemical composition with decrease in magnesium concentration to 98% of the declared value, only in the case of tablets containing magnesium lactate. At 12 months, the magnesium concentration decreased in all analysed samples, with no statistically significant differences (p<0.05) between the types of magnesium compounds – 95% for the orotate, 93% for the lactate, 90% for the oxide and hydroxide, respectively 85% for citrate. The results of this study indicate the therapeutically safety for using these tablets 6 months after the expiry date.